We received an email on the October 15th that the qualification requirements to attend this year’s DARPA Robotics Challenge had been posted on their
website. The new deadline to be invited to run your robot
on the test course was at 5 PM EST on October 31st.

It’s a good thing we monitored the website and
found out about it during the first week in October.

This qualification was in the form of about nine
videos of the robot performing all types of tasks. This
seems like a reasonable request given that they have
spent a great deal of money building robots and funding
the teams in Tracks A–C.

We were a bit stressed since (as a Track D entrant)
we received no DARPA funds, and additionally we have
no corporate sponsorship. We didn’t even have our
biped walking. Biped designs were not required for
these tests that we could easily pass with a rolling robot
and one arm.

1. Translate 12 feet.

2. Go over a six inch high concrete block.

3. Pass through a 32 inch doorway

4. Turn a valve on a wall

5. Demonstrate an E-stop switch.

This was a great deal to accomplish in under four
weeks!

Deadlines

Well, there is nothing like a deadline to make you
productive. We had to work fast. The new servos we
ordered from China were delayed in manufacturing. It
was almost a certainty they would not arrive in time.

Hitec had been advertising some new powered servos
and even sent us a sample, but they were not available in
quantity either. Robotis also sent us one sample of their
new Pro series. Lead time for these was around eight
weeks. We needed a minimum of six servos and could
not afford to buy five more at the price of more than
$2,500 each. What to do?

Yet Another
Complete Rebuild

With time running out, we chose the only option
available. We had some very strong and very affordable
servos from Invenscience. Their Torxis series were priced
under $250 each and boasted a whopping 3,200 oz/in
each. We had four of these and our initial tests proved
that they are monsters. However, they weigh about 1 kilo
each ( 2. 2 lbs) and that would create structural problems.

A complete rebuild was needed to support the weight

by Daniel Albert

48 SERVO 12.2013

The Road
to the DARPA
Robotics
Challenge

Go to www.servomagazine.com/index.php/magazine/
article/december2013_Albert to comment on this article.